from __future__ import annotations

from datetime import datetime, timezone
from uuid import UUID, uuid4

import pytest
from fastapi import HTTPException

from core.auth.models import CurrentUser
from models.agent_chat_session import (
    AgentChatSession,
    AgentChatSessionStatus,
    SessionType,
)
from v1.agent.schemas import RunAgentInput
from v1.agent.service import AgentChatService


class FakeAsyncSession:
    def __init__(self, sessions: list[AgentChatSession]) -> None:
        self._sessions = {session.id: session for session in sessions}
        self.commit_called = False

    async def execute(self, stmt: object):
        class _Result:
            def __init__(self, session_obj: AgentChatSession | None) -> None:
                self._session_obj = session_obj

            def scalar_one_or_none(self) -> AgentChatSession | None:
                return self._session_obj

        for session in self._sessions.values():
            return _Result(session)
        return _Result(None)

    async def scalar(self, stmt: object) -> AgentChatSession | None:
        for session in self._sessions.values():
            return session
        return None

    async def commit(self) -> None:
        self.commit_called = True


def _build_input(run_id: str) -> RunAgentInput:
    return RunAgentInput.model_validate(
        {
            "threadId": "t1",
            "runId": run_id,
            "state": {},
            "messages": [],
            "tools": [],
            "context": [],
            "forwardedProps": {},
            "resume": {"interruptId": "int-1", "payload": {"decision": "approved"}},
        }
    )


@pytest.mark.asyncio
async def test_stream_resume_rejects_non_owner_session() -> None:
    session = AgentChatSession(
        id=uuid4(),
        user_id=uuid4(),
        session_type=SessionType.CHAT,
        status=AgentChatSessionStatus.RUNNING,
        state_snapshot={
            "version": 2,
            "pending_tool_call": {
                "interrupt_id": "int-1",
                "tool_name": "srv.transfer_funds",
                "tool_args": {"to": "u2", "amount": 100},
                "status": "PENDING_APPROVAL",
                "expires_at": datetime.now(timezone.utc).isoformat(),
                "decision": None,
                "result": None,
                "updated_at": datetime.now(timezone.utc).isoformat(),
            },
            "run_context": {"thread_id": "t1", "run_id": str(uuid4())},
        },
    )
    service = AgentChatService(
        session=FakeAsyncSession([session]),  # type: ignore[arg-type]
        current_user=CurrentUser(id=UUID("00000000-0000-0000-0000-000000000001")),
    )

    with pytest.raises(HTTPException) as exc_info:
        await service.prepare_resume(str(session.id), _build_input(str(session.id)))

    assert exc_info.value.status_code == 404


@pytest.mark.asyncio
async def test_prepare_resume_commits_expired_state_before_410() -> None:
    owner_id = UUID("00000000-0000-0000-0000-000000000001")
    session = AgentChatSession(
        id=uuid4(),
        user_id=owner_id,
        session_type=SessionType.CHAT,
        status=AgentChatSessionStatus.RUNNING,
        state_snapshot={
            "version": 2,
            "pending_tool_call": {
                "interrupt_id": "int-1",
                "tool_name": "srv.transfer_funds",
                "tool_args": {"to": "u2", "amount": 100},
                "status": "PENDING_APPROVAL",
                "expires_at": "2000-01-01T00:00:00+00:00",
                "decision": None,
                "result": None,
                "updated_at": datetime.now(timezone.utc).isoformat(),
            },
            "run_context": {"thread_id": "t1", "run_id": str(uuid4())},
        },
    )
    fake_db = FakeAsyncSession([session])
    service = AgentChatService(
        session=fake_db,  # type: ignore[arg-type]
        current_user=CurrentUser(id=owner_id),
    )

    with pytest.raises(HTTPException) as exc_info:
        await service.prepare_resume(str(session.id), _build_input(str(session.id)))

    assert exc_info.value.status_code == 410
    assert fake_db.commit_called is True